Optimize perl code - perl

Question

I have to write to check array ref for more than 3 params. If the value is coming from an array then I have written a foreach loop for that, then chop that and assign to a new variable after concatenating pipe.
Code
if ( defined $args->{hotel} ) {
if ( ref( $args->{hotel} ) eq "ARRAY" ) {
foreach my $hotel ( #{ $args->{hotel} } ) {
$hotel .= $hotel . "|";
}
chop($hotel);
$args->{hotel_name} = $hotel;
} else {
$args->{hotel_name} = $args->{hotel};
}
} else {
$args->{hotel_name} = $hotel;
}
if ( defined $args->{country} ) {
if ( ref( $args->{country} ) eq "ARRAY" ) {
foreach my $country_name ( #{ $args->{country} } ) {
$country_name .= $country_name . "|";
}
chop($country_name);
$args->{country_name} = $country_name;
} else {
$args->{country_name} = $args->{country};
}
} else {
$args->{country_name} = $country_name;
}
if ( defined $args->{city} ) {
if ( ref( $args->{city} ) eq "ARRAY" ) {
foreach my $city ( #{ $args->{city} } ) {
$city .= $city . "|";
}
chop($city);
$args->{city_name} = $city;
} else {
$args->{city_name} = $args->{city};
}
} else {
$args->{city_name} = $city;
}
I want to write a function for this kind of work so that there will be no repetition of same code. Please help me; how can we do this in Perl?

Answer 1

You can write:
sub convert_to_name ($$) { # ($value, $fallback_name)
my ($value, $fallback_name) = #_;
if (defined $value) {
if (ref($value) eq 'ARRAY') {
return join '|', #$value;
} else {
return "$value";
}
} else {
return $fallback_name;
}
}
$args->{'hotel_name'} = convert_to_name $args->{'hotel'}, $hotel;
$args->{'country_name'} = convert_to_name $args->{'country'}, $country;
$args->{'city_name'} = convert_to_name $args->{'city'}, $city;

Answer 2

There appear to be some potential bugs in your code, the biggest centering around reusing variable names at lower scopes.
However, of course you can add an iteration loop to your code that would remove the need for 3 nearly identical sections. The following does that by creating a intermediate hash data structure to relate field names to values.
Note: I also simplified the code by inverting the logic if your first if statement so that all ifs could be at the same level. Additionally, it makes sense to use a join instead of rolling your own such functionality.
my %hash = (
hotel => $hotel,
country => $country_name,
city => $city,
);
while ( my ( $field, $value ) = each %hash ) {
if ( !defined $args->{$field} ) {
$args->{"${field}_name"} = $value;
} elsif ( ref( $args->{$field} ) eq "ARRAY" ) {
$args->{"${field}_name"} = join '|', #{ $args->{$field} };
} else {
$args->{"${field}_name"} = $args->{$field};
}
}
Also, if you're comfortable with the Conditional operator, this can be reduced further. However, some would consider this too cluttered:
while ( my ( $field, $value ) = each %hash ) {
$args->{"${field}_name"} = !defined $args->{$field}
? $value
: ref( $args->{$field} ) eq "ARRAY"
? join( '|', #{ $args->{$field} } )
: $args->{$field};
}